Roof mounted ventilation assembly

ABSTRACT

A roof mounted ventilation assembly having an integrated supply and relief fan assembly. The assembly is drum shaped with a central portion circumferentially defined by centrifugal blades that extend between top and bottom plates. Both top and bottom plates have a central opening, respectively, and axial supply fan blades are disposed within the central opening of the top plate. A supply duct extends through the central portion, fluidly coupling the central openings. The supply duct fluidly communicates a roof-mounted air intake to a supply discharge plenum operatively associated with an interior space. An inlet collar is fluidly couples the remainder of the central portion not closed off by the supply duct to the interior space, wherein relief air in this remainder of the central portion is urged by the centrifugal blades out exhaust ducts to the external environment in a direction transverse relative to axial supply air.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of U.S. non-provisionalapplication Ser. No. 15/929,392, filed 30 Apr. 2020, as a continuationin part thereof, and U.S. provisional application No. 62/840,531, filed30 Apr. 2019, the contents of which are herein incorporated byreference.

BACKGROUND OF THE INVENTION

The present invention relates to a roof mounted ventilation assemblyand, more particularly, to a roof mounted ventilation assembly thatintegrates supply and relief fans.

Most industrial ventilation consists of only relief fans which makes theventilated space negatively pressurized; negatively pressured spacesbring in dirty air and can draw in air from any location (including fluevents).

Ventilation systems with separate supply and relief fans have their owndisadvantages: from being oversized, less efficient and having a ratioof supply to relief air ratio that can be difficult to maintain.Separate supply and relief fans can also be much less effectivedepending on where they are required to be located relative to eachother. Separate supply and relief fans are also more expensive toinstall. Separate supply and relief fans are typically over designedwhen operated in conjunction, and so separate supply and relief fanventilation systems are typically not balanced properly and are neverchecked for air balance when started up. Separate supply and relief fansare not typically installed near each other. Thus, the advantageouseffectiveness of moving air in low and out high (at the same location)is then typically lost on these ‘Frankenstein’ ventilation systems.Furthermore, separate supply and relief fans are more expensive toinstall with separate roof curbs, roof openings, structural supports,power feeds, motors, controllers, etc.

As can be seen, there is a need for a roof mounted ventilation assemblythat integrates supply and relief airflow in one assembly. The assemblyof the present invention assembly solves the following problems:sourcing and installing separate larger, inefficient supply and relieffans with separate control and air distribution components forindustrial ventilation applications; replacing relief-only assemblieswhich depressurizes the space, draws dirty ambient air in from allopenings (including such things as flue vents) and also leaves stagnantareas with no air movement; and recirculating contaminants from otherroof equipment discharges and/or the swirl effect (eddies) of roofplumes from prevailing winds.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a roof mounted ventilationsystem for a structure includes the following: an integrated supply andrelief fan assembly mounted to an upper portion of the structure; an airinlet disposed above and relative to the integrated supply and relieffan assembly; a supply discharge plenum fluidly coupled to the air inletby way of a supply conduit, wherein the supply discharge plenum isdisposed in an interior space of the structure; and the integratedsupply and relief fan assembly comprising a supply axial fan portion anda relief centrifugal fan portion, wherein the supply axial fan portionis fluidly coupled to the supply conduit, wherein the supply fancomprising a plurality of axial fan blades, and wherein the reliefcentrifugal fan portion fluidly couples the interior space with anexternal environment, whereby the supply axial fan portion draws in asupply air flow from the air inlet.

In another aspect of the present invention, the roof mounted ventilationsystem further includes wherein a direction of a relief air flow urgedby the relief centrifugal fan portion to the external environment istransverse relative to a direction of the supply air flow, wherein therelief centrifugal fan portion comprises backward inclined centrifugalblades, wherein the relief centrifugal fan portion comprises backwardincline or forward curved centrifugal blades, further including a driveshaft operatively associated with the integrated supply fan and therelief fan assembly to drive both the supply axial fan portion and therelief centrifugal fan portion, wherein the drive shaft selectivelypressurizes the interior space through a ratio of the supply air flow toa relief air flow.

In yet another aspect of the present invention, an integrated supply andrelief fan assembly for a roof mounted ventilation system for astructure includes the following: a central portion circumferentiallydefined by a plurality of centrifugal blades that extend between top andbottom plates; each said plate having a central opening; an axial supplyfan disposed within the central opening of the top plate; a supply ductextending through the central portion, fluidly coupling the centralopenings; and the plurality of centrifugal blades fluidly communicateswith a remainder portion of the central portion outside the supply duct.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdrawings, description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational cross section view of an exemplary embodimentof the present invention.

FIG. 2 is a perspective cross section view of an exemplary embodiment ofthe present invention.

FIG. 3 is a perspective view of an exemplary embodiment of a combinationsupply blade and exhaust wheel of the present invention, illustrating abackward curved or incline blade configuration of the centrifugalblades.

FIG. 4 is a detailed perspective view of the integrated supply andrelief fan assembly 230 of an exemplary embodiment of the presentinvention, illustrating the direction of the relief air relative to thesupply air.

FIG. 5 is a perspective view of an alternative embodiment of theintegrated supply and relief fan assembly 230 of the present invention,illustrating a forward curve blade configuration of the centrifugalblades.

FIG. 6 is a diagrammatical schematic view of an exemplary embodiment ofthe present invention, illustrating supply air (shown verticallydownward) and relief air flow (being exhausted laterally) through thesystem.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplatedmodes of carrying out exemplary embodiments of the invention. Thedescription is not to be taken in a limiting sense but is made merelyfor the purpose of illustrating the general principles of the invention,since the scope of the invention is best defined by the appended claims.

Broadly, an embodiment of the present invention provides a roof mountedventilation assembly having an integrated supply and relief fanassembly. The assembly is drum shaped with a central portioncircumferentially defined by centrifugal blades that extend between topand bottom plates. Both top and bottom plates have a central opening,respectively, and axial supply fan blades are disposed within thecentral opening of the top plate. A supply duct extends through thecentral portion, fluidly coupling the central openings. The supply ductfluidly communicates, by way of the axial supply fan blades aroof-mounted air intake to a supply discharge plenum operativelyassociated with an interior space. An inlet collar is fluidly coupled tothe remainder of the central portion not closed off by the supply duct.The inlet collar receives relief air from the interior space that thecentrifugal blades then urge out exhaust ducts to the externalenvironment in a direction transverse relative to air axially urged bythe supply fan blades.

Referring to FIGS. 1 through 6 , the present invention may include aroof mounted industrial ventilation (RMIV) system 10 for a structure.The present invention drives both supply air and relief air with onedrive assembly through embodying an integrated supply and relief fanassembly 230. The RMIV system 10 can be selectively controlled to onlysupply air. By supplying air to the worker space as low as possible andmechanically relieving air up high at and above the roof level, lesstotal air is required to cool the interior space with ambient air. Theintegrated supply and relief fan assembly 230 design also minimizesinternal drag which reduces total break horsepower improving energyefficiency. The integrated supply and relief fan assembly 230 may alsohave a variable frequency drive option for even more total energysavings.

The present invention pressurizes an interior space of the structurewith a positive supply to relief air volume ratio. The filtered inletoption allows for the clean fresh air to the interior space of thestructure for worker health and comfort. Pressurizing the interior spacewith multiple units eliminates stagnant zones.

The RMIV system 10 includes an inlet hood 20 with optional filterssubstantially above the roof level defined by the roof deck 30. Incertain embodiments, the inlet hood 20 may be ten or more feet above theroof level and may be stabilized with guide wires. A round inlet duct 60fluidly couples the inlet hood 20 with a top opening of the integratedsupply and relief fan assembly 40/230 at or just above roof level. Theinlet duct 60 is vertically movable relative to the roof deck 30 so thatthe filtered air inlet hood 20 can intake air at whatever level isneeded to avoid re-circulation of other roof discharge contaminants. Thebottom of the inlet duct 60 may connect to a flange 239 disposed alongthe top opening of the integrated supply and relief fan assembly 230.

A round supply duct 62 depends on a bottom opening of the integratedsupply and relief fan assembly 230 to fluidly couple to a supplydischarge plenum 50 disposed within the interior space of the structure.The supply duct 62 is vertically movable as well as rotatably movable soas to establish a desired elevation of the supply discharge plenum 50.The supply discharge plenum 50 may have a louvered register thatdischarges at whatever level is needed and in whatever direction isneeded allowing for maximized worker comfort.

The filtered intake assembly provides for a pressurized, clean, healthyand comfortable workspace. Combining supply air and relief air throughone assembly 230 and so in one location and at the proper elevationsallows for better efficiency, less total air flow and always positiveratio of supply to relief air. The combined assembly 230 is lessexpensive to install than separate built up supply and relief fans.

The present invention includes the following elements:

Air Inlet Hood 20: This is an air inlet adapted to draw in air with aninverted trapezoid prism shaped hood with a bird screen and optionalfilter 22 with low drag design reducing fan brake horsepower. The basicmodel includes a wire mesh screen with options for multiple MERV levelfilters as the customer desires. The air inlet hood 20 may be fluidlyconnected to the inlet duct 60 by way of a radius inlet cone 220.

Drive Unit 33: The drive unit 33 may include a single motor and driveassembly powering the drive shaft(s) with belts and pulleys or directdrive for the integrated supply and relief fan assembly 230. This mayinclude an optional variable frequency drive motor and a control module.The control module may be a HONEYWELL SPYDER™ series (or equal) withcontrol options to energize the assembly based on external inputs suchas room temperature, humidity, or room pressure.

The integrated supply and relief fan assembly 230: The integrated supplyand relief fan assembly 230 directly connects to the drive unit 33 andcan come with an optional clutch to disengage the blower wheel portion231 of the integrated supply and relief fan assembly 230 from the driveshaft while the supply fan remains energized. The assembly 230 is drumshaped with a central portion 232 circumferentially defined bycentrifugal blades 233 that extend between top and bottom plates 234 and235, respectively. Both top and bottom plates have a central opening236, respectively, and axial supply fan blades are disposedwithin/around the central opening of the top plate. A supply duct 62extends through the central portion 232, fluidly coupling the centralopenings 236. The supply duct 60/62 fluidly communicates a roof-mountedair intake 20 to a supply discharge plenum 50 operatively associatedwith an interior space. An inlet collar 145 may be part of the assemblythat fluidly couples the remainder of the central portion not closed offby the supply duct to the interior space, wherein relief air in thisremainder of the central portion is urged by the centrifugal bladesthrough the exhaust ducts to the external environment in a directiontransverse relative to axial supply air.

A relief assembly 40 for the integrated supply and relief fan assembly230 may include and be fluidly coupled to a conical inletcollar/interior housing 145 and lateral relief louvers. Hot room air atthe roof level may be mechanically drawn up into the blower wheelportion 231 and pushed out through relief louvers. With optionalmotorized actuators, shut off dampers 160 of the relief blower assembly40 could be separately manipulated to change the ratio of supply toexhaust air as desired. Thus, the interior space could be positive,neutral, or slightly negative. Code shut off dampers 160 for both supplyand the relief may be provided, including RUSKIN CD™ series (or equal)sealed shut off dampers.

The supply discharge plenum 50 includes a round conical inlet with around conical bottom pan. Air diffusion may be provided through thesupply discharge plenum 50 via a supply diffuser 150 in a circularpattern (via circumference blades) or rectangular pattern with fourquadrants (with registers on given sides). Horizontal diffusion may befrom adjustable vertical blades 152 around the circumference. Verticaldiffusion may be from adjustable horizontal pitched rings 154. The lowdrag design reduces fan break horsepower.

The inlet hood and the supply discharge plenum may be connected by theinstalling contractor in the field with round spiral type duct MCGILL™(or equal).

The drive unit 33 may include a motor-powered fan blade drive assemblythat draws air in through the conical air inlet hood 20. The fan bladedrive assembly may include a drive assembly belt. The drive unit 33 maybe a belt drive unit, a direct drive unit, and may include optionalvariable frequency drive motor. The drive unit 33 connects to conicalair inlet hood 20 with field installed round duct 60, and the drive unit33 may directly connect to the relief assembly 40 by way of a shaft. Thedrive unit 33 drives the integrated supply and relief fan assembly 230.The relief assembly 40 connects to the inlet hood 20 with a fieldinstalled round duct 60. Field installed code shut off dampers 160 maybe in place to shut when the unit is de-energized per InternationalMechanical Code Requirements.

The RMIV system 10 may be mostly welded steel and aluminum construction.There are screws, filter clips, nuts and bolts for some components. Themain components may be factory built. The RMIV system 10 may then beconstructed in the field as noted below: Field installation is verysimilar to most existing packaged rooftop fan assemblies. In thatregard, the RMIV system 10 may be installed in the field (at theindustrial facility) mostly by a qualified mechanical contractor.Installation may also include crane, electrical, controls, steel androofing contractors. A curb 120 may be installed over the appropriatesize roof opening. The relief shut off dampers 160 may be set on a trayinside the roof curb 120. (Depending on the type of existing roof deck30, the roof opening and roof structure 30 may have to be re-enforced toaccept the new unit.) The relief assembly 40 may then be placed on theroof deck 30 The drive unit 33 may be then connected to the reliefassembly 40. The air inlet hood 20 may then be set at the desiredelevation with field supplied round spiral duct. (Depending on localcode and/or the desired height, guide wires may need to be connected tostabilize the unit.) Finally, inside the space 80, the supply dischargeplenum 50 may be set at the desired elevation (and/or rotation) withfield supplied spiral duct.

The combination supply and relief fan assembly(s) are placed as neededin industrial facilities (and/or warehouses) to improve comfort and airquality for the cooling season. The one or more RMIV systems 10 replacesexisting exhaust fans meant for cooling season comfort ventilation. Theone or more RMIV systems 10 provide clean filtered air to thestructure's interior space 80. The positive supply to relief air volumeratio remains constant at all speeds keeping the space pressurized andthereby keeping contaminants out. Constant positive space pressure keepssuch items as flue vents pushing out and not recirculating back into thespace.

The field supplied round spiral duct may be custom fit to place theinlet hood and supply discharge plenum as needed at any given locationin an industrial facility. Also, the inlet hood 20 and the supplydischarge plenum 50 can be moved up and down (relatively easily) whilethe base unit remains connected if field conditions change. The variablespeed drive unit 33 allows the supply to relief air volume to adjust upand down in the same proportion keeping the space positive.

The present invention may further include an assembly controller thathas options to energize the assembly based on external inputs such asroom temperature, humidity or room pressure. With optional motorizedactuators, the shut off dampers 160 could be separately manipulated tochange the ratio of supply to exhaust air as desired. The space could bepositive, neutral, or slightly negative.

The present invention may come with a built-in inlet bird screen.However, inlet filters and/or the filter type (i.e., the filter MERVrating) are optional. The motor type (i.e., open drip proof, totallyenclosed, starter or VFD drive) is optional. The controls may be eithersimple on/off or variable speed with a user interface on the interior ofthe building or there may be an option for BacNET control via a buildingautomation system. With optional motorized actuators, the shut offdampers 160 could be separately manipulated to change the ratio ofsupply to exhaust air as desired. The space could be positive, neutral,or slightly negative. The code shut off damper type at the roof levelmay be optional based on local code. The discharge registers type mayalso be optional.

The concept could be used for other process or modular room applicationswhere the total air volume may be required to change but the supply torelief air volume needs to remain positive keeping the space positive. Adirect fired heating option can be added in the supply duct 62 toconvert this into a direct fired heating unit. The heating unit may bebolted on and is like a CAPTIVE AIRE™ or POWER FLAME™ equivalent directfired burner heating unit.

As used in this application, the term “about” or “approximately” refersto a range of values within plus or minus 10% of the specified number.And the term “substantially” refers to up to 80% or more of an entirety.Recitation of ranges of values herein are not intended to be limiting,referring instead individually to any and all values falling within therange, unless otherwise indicated, and each separate value within such arange is incorporated into the specification as if it were individuallyrecited herein.

For purposes of this disclosure, the term “aligned” means parallel,substantially parallel, or forming an angle of less than 35.0 degrees.For purposes of this disclosure, the term “transverse” meansperpendicular, substantially perpendicular, or forming an angle between55.0 and 125.0 degrees. Also, for purposes of this disclosure, the term“length” means the longest dimension of an object. Also, for purposes ofthis disclosure, the term “width” means the dimension of an object fromside to side. For the purposes of this disclosure, the term “above”generally means superjacent, substantially superjacent, or higher thananother object although not directly overlying the object. Further, forpurposes of this disclosure, the term “mechanical communication”generally refers to components being in direct physical contact witheach other or being in indirect physical contact with each other wheremovement of one component affect the position of the other.

The use of any and all examples, or exemplary language (“e.g.,” “suchas,” or “the like”) provided herein, is intended merely to betterilluminate the embodiments and does not pose a limitation on the scopeof the embodiments or the claims. No language in the specificationshould be construed as indicating any unclaimed element as essential tothe practice of the disclosed embodiments.

In the following description, it is understood that terms such as“first,” “second,” “top,” “bottom,” “up,” “down,” and the like, arewords of convenience and are not to be construed as limiting termsunless specifically stated to the contrary.

It should be understood, of course, that the foregoing relates toexemplary embodiments of the invention and that modifications may bemade without departing from the spirit and scope of the invention as setforth in the following claims.

What is claimed is:
 1. A roof mounted ventilation system for astructure, the system comprising: an integrated supply and relief fanassembly mounted to an upper portion of the structure; an air inletdisposed above and relative to the integrated supply and relief fanassembly; a supply discharge plenum fluidly coupled to the air inlet byway of a supply conduit, wherein the supply discharge plenum is disposedin an interior space of the structure; and the integrated supply andrelief fan assembly comprising a supply axial fan portion and a reliefcentrifugal fan portion, wherein the supply axial fan portion is fluidlycoupled to the supply conduit, wherein the supply fan comprising aplurality of axial fan blades, and wherein the relief centrifugal fanportion fluidly couples the interior space with an external environment,whereby the supply axial fan portion draws in a supply air flow from theair inlet.
 2. The system of claim 1, wherein a direction of a relief airflow urged by the relief centrifugal fan portion to the externalenvironment is transverse relative a direction of the supply air flow.3. The system of claim 1, wherein the relief centrifugal fan portioncomprises backward inclined centrifugal blades.
 4. The system of claim1, wherein the relief centrifugal fan portion comprises forward curvedcentrifugal blades.
 5. The system of claim 1, further comprising a driveshaft operatively associated with the integrated supply fan and therelief fan assembly to drive both the supply axial fan portion and therelief centrifugal fan portion.
 6. The system of claim 2, wherein thedrive shaft selectively pressurizes the interior space through a ratioof the supply air flow to a relief air flow.
 7. An integrated supply andrelief fan assembly for a roof mounted ventilation system for astructure, the assembly comprising: a central portion circumferentiallydefined by a plurality of centrifugal blades that extend between top andbottom plates; each said plate having a central opening; an axial supplyfan disposed within the central opening of the top plate; a supply ductextending through the central portion, fluidly coupling the centralopenings; and the plurality of centrifugal blades fluidly communicateswith a remainder portion of the central portion outside the supply duct.